Numerous recent studies have undercut the purported benefits of various herbal supplements. Gingko, echinacea and Saint John's wort, have all been found relatively ineffective against many of the ills they have been claimed to help.

This does not seem to have slowed purchases by U.S. consumers, who spent $14.8 billion on these and other natural supplements in 2007, according to a report released last summer.

It also hasn't stopped many supplement sellers from making the false claims and even recommending potentially dangerous uses of the products to customers, according to a recent investigation conducted by the Government Accountability Office (GAO). To obtain a sample of sales practices, the agency got staff members to call online retailers and to pose undercover as elderly customers at stores selling supplements.

Customers were not only told that supplements were capable of results for which there is no scientific evidence (such as preventing or curing Alzheimer's disease); the advice and information also was potentially harmful (including a recommendation to replace prescription medicine with garlic). Excerpts from secretly recorded conversations are available on the GAO's Web site.

Both the U.S. Food and Drug Administration (FDA) and Federal Trade Commission (FTC) found the practices "improper and likely in violation of statutes and regulations," according to the report, which was delivered as testimony on May 26 by Gregory Kutz, managing director of Forensic Audits and Special Investigations at the GAO, to the U.S. Senate Special Committee on Aging.

But the potential for harm did not appear to end with marketing and staff recommendations. Following up on previous studies that had found contaminants and other adulterants in herbal supplements—which are regulated by the FDA as food products, not drugs, and thus not subject to pre-market approval or testing—the GAO sent bottles of 40 commonly purchased supplements to a lab for testing.

The lab found 92 percent of the tested herbal supplements (which included pills, capsules and other products derived from plant products but not vitamins) contained trace amounts of lead and 80 percent had at least one other contaminant, such as mercury, cadmium and/or arsenic. The levels (none were more than 0.05 part per million) did not exceed what the FDA and U.S. Environmental Protection Agency (EPA) currently considers hazardous, but, notes Marcus Reidenberg, chief of the Division of Clinical Pharmacology at New York–Presbyterian Hospital/Weill Cornell Medical Center, "ingesting these heavy metals is of no benefit." And the GAO report states that "consuming high levels of the contaminants for which we tested…can lead to severe health consequences, such as increased risk of cancer."

The supplement industry shared the concern raised by the report, Steve Mister, president of the Council for Responsible Nutrition, one of several supplement trade groups, said in Senate testimony also delivered May 26. But, he noted that "the majority of American consumers who take dietary supplements are using safe, high-quality supplements to maintain and improve their healthy lifestyles," and also pointed out that "pharmaceuticals, conventional foods, medical devices and cosmetics—all regulated by FDA—likewise have accidents and rogue players." Regarding the GAO's findings, he had told The New York Times he did not think they "should be of concern to consumers."

Label liability
Millions of Americans continue to buy herbal supplements based on the belief that they will improve their quality of life. But just what goes into these supplements and what body part or function they purport to help is largely up to the product's manufacturer.

All dietary supplements, including herbal supplements, vitamins, enzymes and other substances, are regulated by the FDA under the 1994 Dietary Supplement Health and Education Act, which says that only the manufacturers are responsible for making sure a supplement is safe—and recommending how much a consumer should take. It also mandates that only manufacturers need to determine if a supplement can stand up to claims made about its benefits. And, as noted on the FDA's Web site, supplement-makers are not required to present any information to the government about how they arrived at safety and effectiveness conclusions.

As with other food products, the FDA conducts routine monitoring of products and inspections of manufacturing processes, but it does not evaluate supplements before they hit the shelves to see if the ingredients match those listed or that the ingredients—listed or unlisted—are of safe levels. And if a product appears to be causing harm, it is up to the FDA to "demonstrate that the dietary supplement presents a significant or unreasonable risk" before it can be pulled from the shelves, the report pointed out.

In labeling supplement-makers cannot claim a product will cure, treat or prevent a specific condition, as that would make it a drug. Instead, labels can boast of general "body function claims," such as "aids digestion," "improves heart health" or "boosts brain function" etcetera, says Paul Shekelle, an internist at the West Los Angeles Veterans Affairs Healthcare Center and director of the Southern California Evidence-Based Practice Center at the RAND Corp. Although these claims must be followed by a standard, asterisked FDA disclaimer ("This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent any disease."), people often do not get the right message, Shekelle says.

"Those distinctions can be confusing to consumers," who often might not have all of the information to separate body-function statements (such as "boosts brain function") from specific treatment indications that they might be seeking (for example, "prevents Alzheimer's"), he notes. And messages can get mixed when a sales associate steps in to do the interpretation for consumers.

Because the FDA is in charge of keeping track of what's on a supplement's packaging, whereas FTC watches for false claims in advertisements, few eyes are turned to the individuals who are selling products and engaging in conversation with a potential customer.

Sales calls
To see just how these supplements were being sold to customers, the GAO sent the undercover staff members to ask questions of 22 storefront and mail-order supplement retailers in 2009 and 2010. The agency focused on consumers over the age of 65 who have been shown to be taking an increasing amount of supplements, 85 percent of whom are on at least one prescription medication a year (with which a supplement could potentially interact). For example, Saint John's wort, sometimes marketed for depression, has been shown to decrease the effectiveness of prescribed antidepressants—as well as some cancer drugs, HIV treatments and anticoagulants, according to the report.

Should an elderly person take gingko biloba with aspirin? Can ginseng cure cancer? What about replacing prescribed blood pressure medication with garlic supplements? All resounding yes's from supplement sales staffs, the GAO found in its undercover investigation—but big no's per the National Institutes of Health (NIH). Taking a combination of gingko and aspirin can increase the risk of internal bleeding. Ginseng has not been proved to cure any diseases, and should be avoided for those with breast and uterine cancers, according to the NIH. Garlic has not been proved to significantly lower high blood pressure—and supplements are not intended to replace prescribed drugs.

The statements by supplement seller staff members amount to "unequivocal deception," Reidenberg says.

Industry representative Mister noted in his testimony that "making false or misleading statements about a dietary supplement in a consumer transaction violates many states' consumer protection, anti-fraud and unfair competition statutes." He also added that he was not sure "whether the retailers in the GAO's investigations are aware that they are breaking the law."

The inaccuracies might not be intentional on a staff member's part, Reidenberg points out. "You don't know what these employees truly believe," he says. And if a sales associate reads a supplement's package without giving proper weight to the FDA's disclaimer, they could conceivably construe a product's stated benefits, such as "improves heart health," as proof of effectiveness in actually preventing or treating cardiovascular disease.

And even for some consumers, sales pitches aside, Reidenberg says, "they just believe in them, and that's that." But he worries that as the amounts of prescription medications and supplements a person takes increase, consumers will eventually become adverse to swallowing the sheer number of pills, as taking a large number of any pill—even placebos—has been shown to create digestive problems. "If someone has eight tablets for necessary medicine and 12 tablets for supplements, then which ones are they going to not take when they don't feel good?" he asks.

Additionally, many of these supplements have side effects that consumers—and some doctors—might not know, or know to ask about. But awareness has been increasing, Shekelle notes. Unlike 15 years ago, he says, at his hospital if someone is planning to get surgery, "we regularly ask if they take gingko because it increases the bleeding time."

The big question, as Shekelle sees it, however, is not whether customers should want to spend their money on products of questionable efficacy, but whether "taking this stuff is not going to be deleterious to their health."

Contaminated goods
Even if the labels of some of these supplements might give consumers—or sales staff—confusing ideas about efficacy, what is not on the labels could be even more harmful.

Of the 40 herbal supplements tested for the GAO investigation, 37 contained trace levels of at least one hazardous compound. These heavy metal levels are down from a 2004 study, published in JAMA The Journal of the American Medical Association, which found dangerous levels of heavy metals in 20 percent of herbal supplements tested. Despite a plea by those study authors for "mandatory testing of all imported dietary supplements for toxic heavy metals," the FDA only requires pre-market evaluation of products containing any "new dietary ingredient" that has not previously been used in a supplement.

Levels of exposure, however, depend on how much of a supplement a person takes, notes Reidenberg, who says some people think that if "a little is good, more is better, and a lot must be great." Thus, "the total dose might be more than anticipated," he says.

The lab also tested the supplements for pesticides and found that 18 of 40 contained traces of at least one formula. Although the EPA sets limits for many pesticides, if a pesticide has not been sufficiently evaluated to have an established maximum level, any amount is considered too much. Sixteen of the supplements thus exceeded the acceptable pesticide levels, and four of the pesticide residues were from formulas not approved for use in the U.S., according to the report.

Although the GAO analysis did not test for other ingredients, such as other herbs or compounds, other analyses have found everything from steroids to active pharmaceuticals in herbal supplements, Shekelle notes.

"This goes back to the presumption that dietary supplements are safe," he says. As food products, supplements are considered safe until proved otherwise by the FDA. But, he notes, "I don’t think we have a universal definition of what is 'safe'." He is quick to add that anything can be risky, from water to the drugs he prescribes for his patients. "I prescribe things that have risk all the time, but I do so when I think that the chance of benefit exceeds the chance of risk enough to make it worth it."

Thus, even if levels of contaminants are low, Shekelle wonders "How much risk is it reasonable to ask customers to take on?" And particularly in the realm of herbal supplements with tenuous track records of efficacy, he adds, "If there's no proven benefit, then there shouldn't be any risk at all."

Supplementing safety
To be sure, the contaminants and even the questionable marketing practices are not new to people who have been following this topic in recent years. "There have been examples of this in the literature for a while," Reidenberg says.

But the GAO report adds new weight to the issue. It was released May 26, weeks before an anticipated June Senate debate of a food safety bill. And discussion about the regulation of these products will likely come up. The supplement industry, however, is likely to fight additional regulation, which Mister called "burdensome" in his testimony, noting that the industry associations have stepped up their efforts to improve inspection and regulation of member companies. "More than ever, dietary supplement manufactures have every incentive to produce the best quality products, and real sanctions in place if they don't."

Not everyone has remained unperturbed by this or previous reports of supplement-makers' dubious marketing practices or hazardous contents. "For a product that's assumed to be safe and for which the health benefits are tenuous or unproven, I think that's a legitimate issue," says Shekelle, who would welcome hard evidence to back up health claims. And he is not satisfied with in vitro assays testing isolated compounds on isolated cells: "If it's going to [say] garlic helps high blood pressure, then there better be studies in humans that show garlic helps high blood pressure," he says.